wesmc Posted February 27, 2013 Share Posted February 27, 2013 71 240z, L28 block clearanced for valves, port'n'polish head, 280z valves, flat tops, SK carbs, conservative race/aggressive street cam. Stock 4 speed for the time being, plan to go 5-speed after recovering from the $$ spent so far. Motor turns very strong but now the one wheel squeal is unbearable. Reading and reading tells me go with the subie 180lsd and get Johnc's side axles. Car is at 2200lb, less than 210rwhp, and is road race only, will never drag race. Am I on the right track? Quote Link to comment Share on other sites More sharing options...
OldAndyAndTheSea Posted February 27, 2013 Share Posted February 27, 2013 Sounds wicked fun to me! You're definitely on the right track. Quote Link to comment Share on other sites More sharing options...
johnc Posted February 27, 2013 Share Posted February 27, 2013 The OS Giken Super Lock would be a better choice for a pure road race car. Its more expensive but a much better diff. 1 Quote Link to comment Share on other sites More sharing options...
wesmc Posted February 28, 2013 Author Share Posted February 28, 2013 Thanks John. I did get a bit of a shock when I saw the price, no cheaper than when we put them in the Porsche cars. In the Z is less understeer and greater durability why the Giken is preferred? Quote Link to comment Share on other sites More sharing options...
johnc Posted February 28, 2013 Share Posted February 28, 2013 Its just a much better design overall. 10 clutches on each side, progressive lock timing, up to 100% lock, and a very smooth, progressive lockup. I did a little bit of crewing with a World Challenge Viper team in 2008 during a test at WSIR where they swapped out diffs. The wheel speed traces for the OS Giken were like a smooth hourglass compared to the stepped traces from two other CLSDs. The driver felt the OSG was much easier to drive and his laps times were better. I also had a customer who won the Solo2 FP national championship (finally beating John Thomas) in a E38 BMW. A huge part of his time improvements was the OSG Super Lock and some very specific tuning OSG did. He was getting a slight push from the thrid cone on during a slalom. OSG detemined that the flat clutch plates were locking a bit harder then they should because the gear oil was pumped out by the throttle on-off-on-off-on during his slalom runs.OSG came down to my shop and showed me how to install a set of their TCD plates which have small oil grooves. This solved the problem. Pics are here:http://www.facebook.com/media/set/?set=a.464901636670.254755.143989191670&type=3Full disclosure: I sell the whole OSG product line. 1 Quote Link to comment Share on other sites More sharing options...
wesmc Posted February 28, 2013 Author Share Posted February 28, 2013 I think you sold me. This car started out as a budget build made mostly from stuff we had. That is already waay out the window so I might as well go all in. Quote Link to comment Share on other sites More sharing options...
Cobra_Tim Posted March 6, 2013 Share Posted March 6, 2013 Hey John... It seems like we've burned up our subie diff... Whats the best way to rebuild or shim the thing to get it back into spec? Sorry for the thread hijack... at least its on the same topic. 1 Quote Link to comment Share on other sites More sharing options...
Warren Posted March 6, 2013 Share Posted March 6, 2013 *Thread moved from Events forum to Drivetrain forum* Quote Link to comment Share on other sites More sharing options...
johnc Posted March 7, 2013 Share Posted March 7, 2013 Hey John... It seems like we've burned up our subie diff... Whats the best way to rebuild or shim the thing to get it back into spec? Sorry for the thread hijack... at least its on the same topic. Its a regular CLSD (I assume) so most diff shops can rebuild it. Parts are available from Subaru. Then add a diff cooler and change the fluid regularly. Quote Link to comment Share on other sites More sharing options...
duragg Posted March 7, 2013 Share Posted March 7, 2013 My LSD is the single most enjoyable mod I've done. Probably need to think about changing the juice and the cooler as mentioned. Quote Link to comment Share on other sites More sharing options...
5thgenluder Posted March 9, 2013 Share Posted March 9, 2013 John would an OSG diff for a r180 hold up well to an rb25det swapped s30? I plan to be in the range of 400hp and similar torque levels. Or would I need to go r200? Quote Link to comment Share on other sites More sharing options...
johnc Posted March 13, 2013 Share Posted March 13, 2013 You need to go R200 for that power level. Quote Link to comment Share on other sites More sharing options...
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